1. Field of the Invention
The present invention is directed to a cassette loading device, and more particularly, to a cassette loading device for automatically guiding a cassette to a recording and/or reproducing device and loading it therein.
2. Description of the Related Art
This kind of cassette loading device has heretofore been employed for, for instance, a helical scan type VTR. The description in the specification of the present invention will therefore be made by exemplifying the cassette loading device employed for the VTR of this type.
Especially, a so-called installation type VTR which performs picture recording/reproducing operations in TV broadcasting is in general invested with a function to automatically guide a cassette holder from a position in which the user inserts it to a position in which the picture recording/reproducing operations can be carried out. The cassette and the holder for holding the cassette are guided to a predetermined position within the VTR body and are then loaded therein simply by inserting the cassette into a insertion port with the help of, for example, a so-called front loading mechanism. In that position, the picture recording/reproducing operations are effected while winding a tape of the cassette on a rotary drum by a so-called tape loading mechanism.
In the above-described device, however, the cassette is automatically loaded by moving a holding member (a cassette holder) for holding the cassette after detecting such a step that the cassette has been inserted by the user and the cassette holder has moved a given distance away from an initial position. For this reason, it is required to detect the position of the predetermined distance at which the cassette holder moves. Upon a completion of the loading of the cassette, the cassette holder has to cease its movement and hence it is necessary to detect the position of the cassette holder just when completing the loading of the cassette.
When taking out the cassette, it is also needed to detect the fact that the cassette holder is in the intial position because of the necessity for halting the movement of the cassette holder after making the cassette holder revert to the initial position in the light of facilitating the operation of taking out the cassette.
A plurality of positions of the cassette holder are spaced away from each other on the device. Therefore, if a detecting switch is provided on the side of the device body, a cord (a wire) for obtaining a signal from the detecting switch increases in length, this conducing to defects wherein the VTR becomes intricate of constituion and both miniaturization and reduction in weight of the device are hindered.
The switch is attached to the cassette holder, which arrangement requires a single switch alone. However, the wire also undesirably moves when installing the wire to the movable holder.
Such is the general constitution that, when the user inserts the cassette in the VTR, unless a certain surface of the cassette has to be turned in a predetermined direction, the insertion is not made at all. Inasmuch as the individual surfaces of the tape cassette commonly, as illustrated in FIG. 1, assume different configurations from each other, the insertion of an erroneous surface of the cassette or in an erroneous direction (misinsertion) is prohibited by mechanically or electrically detecting the difference in configuration. With this arrangement, the cassette 1 is, as indicated by an arrowhead 2 of FIG. 1, invariably inserted into the cassette insertion port (shown by the numeral 3 of FIG. 1) formed in the VTR body.
Even in the case of inserting the proper surface of the cassette into the cassette insertion port or inserting it in the adequate direction, however, an abrupt insertion of the cassette causes impact on the cassette holder, whereby a mechanism for driving the cassette holder does not normally function in some cases. This will bring about damages in the cassette, the holder mechanism, the tape and so on.